Jimmy Fallon receives harsh advice from Howard Stern

The callous Stern turned from guest to critic during "Late Night With Jimmy Fallon" on Monday night. "You're competing against Letterman, Jimmy Kimmel," he shot at the host. "It's a jungle — you don't have the killer instinct." Someone out there must like Fallon, though; the comedian's...

The callous Stern turned from guest to critic during "Late Night With Jimmy Fallon" on Monday night. "You're competing against Letterman, Jimmy Kimmel," he shot at the host. "It's a jungle — you don't have the killer instinct." Someone out there must like Fallon, though; the comedian's... (Theo Wargo / Getty Images)

The callous Stern turned from guest to critic during "Late Night With Jimmy Fallon" on Monday night. "You're competing against Letterman, Jimmy Kimmel," he shot at the host. "It's a jungle — you don't have the killer instinct." Someone out there must like Fallon, though; the comedian's...Theo Wargo / Getty Images